Friction-driven rotary cleaning apparatus with coaxial transmission

ABSTRACT

This disclosure depicts floor and ground cleaning apparatus having a cylindrical brush which is friction driven from a pair of wheels through novel transmission means coaxial with the brush and the wheels.

United States Patent Coult [54] F RICTION-DRIVEN ROTARY CLEANING APPARATUS WITH COAXIAL TRANSMISSION Inventor: John I-I.' Coult, One Leland Road,

Natick, Mass. 01760 Filed: April 19, 1971 Appl. No.: 135,142

US. Cl. ..15/49 C Int. Cl. ..A471 11/22 Field of Search ..15/4148, 49 C,

[ 51 Sept. 19,1972

[56] References Cited UNITED STATES PATENTS 1,143,840 6/1915 Lelong ..l5/4l R FOREIGN PATENTS OR APPLICATIONS 601,813 3/1926 France ..15/49 C Primary Examiner-Edward L. Roberts [57] ABSTRACT This disclosure depicts floor and ground cleaning apparatus having a cylindrical brush which is friction driven from a pair of wheels through novel transmission means coaxial with the brush and the wheels.

10 Claims, 3 Drawing Figures FRICTION-DRIVEN ROTARY CLEANING APPARATUS WITH COAXIAL TRANSMISSION CROSS REFERENCE TO RELATED APPLICATION BACKGROUND OF THE INVENTION Ground and floor sweepers having a friction-driven rotary brush are well known. This invention concerns improved friction-driven ground and floor cleaning apparatus of the type having a coaxial transmission.

A US. Pat. to Sandberg No. 2,145,738 illustrates a relatively large, heavy, and cumbersome friction-driven rotary sweeper having a four-wheeled carriage, the front wheels of which are steerable by means of an adjustable steering bar forming part of a handle bar assembly. A cylindrical brush is driven from the steerable front wheels through a vertically adjustable transmission, in one position of which the brush axis and the wheel axis are coaxial. The transmission is relatively complex, expensive to manufacture, and susceptible to jamming by dirt and debris, comprising two sets of 45 bevel gears interconnected through an adjustable slider structure.

Prior art cleaning devices such as described are of little or no value for outdoor household and light industrial cleaning wherein compactness, weight, maneuverability, cost and reliability are of major importance.

OBJECTS OF THE INVENTION It is an object of this invention to provide improved apparatus for cleaning patios, sidewalks, driveways, industrial floors, and the like which has very high cleaning efiiciency, and which is extremely lightweight and compact, highly maneuverable and generally easy and convenient to use.

It is a primary object of this invention to provide such cleaning apparatus having a surface treating tool such as a cylindrical brush which is friction driven from a pair of end wheels through a coaxial transmission which is substantially immune to clogging by dirt and otherwise highly reliable and yet which is relatively inexpensive to manufacture.

It is another object to provide such cleaning apparatus having a strong yet lightweight housing which, inter alia, compactly, efficiently, and economically supports a novel coaxial transmission to make possible, in part, the above-stated objects of lightness, compactness, and general ease and convenience of use.

Further objects and advantages of the invention will in part be obvious and will in part become apparent as the following description proceeds. The features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of sweeping apparatus embodying this invention;

FIG. 2 is a fragmentary front elevational view, partly broken away, of the right end of the Fig. l apparatus; and

FIG. 3 is a perspective view of the coaxial transmission depicted in FIGS. 1-2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Figures 1 3 illustrate a sweeping device 10 representing one of the many devices contemplated for implementing the principles of this invention. The device 10 is illustrated as including a support structure in the form of a housing 12 which supports for rotation a cylindrical brush 14 having a shaft 15. The housing 12 is shown as being of stamped sheet metal construction, but may alternatively be of molded plastic or other suitable constructions.

The device 10 includes a pair of wheels l6, 17 having stub axles 18, 19. The stub axles 18, 19 of wheels 16, 17 may be integral with the wheels 16, 17 or may be inde pendent members. The wheels 16, 17 are shown as each including a hub 20 receiving an elastic tire 22 of high friction material.

The brush 14 is here shown as being of a construction known as twisteddn-wire"; however, the brush may be of the tufted-axle, or strip types or of any other suitable construction.

The construction and functions of the housing 12 will now be discussed. The housing 12 has a number of significant functions. First, it provides a strong but lightweight exoskeleton for the device and (as explained in detail below) includes support means which rotatably support the ends of the brush shaft 15 and the stub axles 18, 19 carrying the wheels 16, 17. More particularly, the housing 12 includes a longitudinal body portion 24 having a lightweight, thin-walled construction, which may be of suitable molded plastic or, as illustrated, of sheet metal. The body portion 24 of the housing 12 has substantial curvature in planes transverse to the brush shaft 15 to provide longitudinal rigidity without a high weight factor.

In addition to providing structural rigidity for the device and supporting the brush 14 and wheels 16, 17 for rotation, the housing 12 also serves to shield the user from flying debris, especially if the device should be pulled backwards so as to rotate the brush 14 in the reverse direction, causing the brush 14 to throw debris toward the user. The housing 12, by virtue of its wraparound construction provides a support edge 26 which protects the brush, for example, in a situation where an elevated patio is being cleaned and one wheel runs off an edge.

The housing 12 has a pair of end walls 28, 29 extending forwardly from the body portion 24 of the housing 12. A handle 30 attached to the housing 12 enables the device to be manually propelled and manipulated.

Friction-driven cleaning apparatus including novel exoskeletal support means, as described above, constitutes the subject matter of another invention of mine disclosed and claimed in the above-referenced copending application.

In accordance with this invention, the device 10 includes a novel coaxial transmission 31 supported on the housing 12 by a bracket 32 between one of the wheels (here shown as right wheel 17) and the brush shaft 15 for coupling wheel 17 and shaft such that rotation of wheel 17 effects an opposite rotation of brush 14. The transmission 31, the wheels 16, 17 and the brush shaft 15 are supported on a common axis A-A.

More particularly, transmission 31 comprises a plate 33 which is driven by wheel 17 through a set of three equi-angularly spaced coupler wheels 34, 36, 38 supported for rotation on a mounting member 40 attached to bracket 32.

The driven plate 33 is illustrated as including a hollow hub 42 which receives the right end of the brush shaft 15 in an interference fit or other arrangement capable 'of precluding relative rotation between the plate 33 and the brush shaft 15. The hub 42 of plate 33 is supported for rotation in an aperture in an arm 44 constituting part of the bracket 32.

The plate 33 has a circular track surface 46 concentric with the axis A-A on which the coupler wheels 34, 36, 38 travel. The track surface 46 is preferably formed as a high friction surface. For example, a ring of radially oriented grooves or other surface irregularities may be formed in the plate 33 to produce the high fn'ction property.

As briefly described above, the coupler wheels 34, 36, 38 are mounted for rotation on mounting member 40. The mounting member 40 is shown as being formed of stamped sheet metal having cut-outs, one of which is shown at 50, for the wheels 34, 36, 38 and on opposite sides of the cut-outs staggered ribs, one set of which is shown at 54. The ribs 54 support axles, two of which are shown at 58 and 60, which mount for rotation wheels 34, 36, 38. The coupler wheels preferably each include a high-friction tire for increasing the frictional forces acting thereon.

The stub axle 19 of wheel 17 is supported for rotation by a bearing 63 held in an aperture in the mounting member 40 and in an aperture in a leaf spring 61 attached to an arm 62 forming part of bracket 32. The spring 61 is discussed in more detail below.

According to this invention, means are provided which rotate with a drive wheel and which have thereon a high friction circular track surface concentric with the axis A-A and disposed in spaced vis-a-vis relationship to the track surface 46 on driven plate 33. In the illustrated preferred embodiment, the trackdefining means constitutes an integral part of the wheel 17 other arrangements, however, are within the purview of this invention. To this end, the wheel 17 is preferably of molded plastic construction and has formed therein surface irregularities defining a circular track surface 64 addressing the track surface 46 on driven plate 33. The surface irregularities may be radial grooves as suggested above in connection with the description of track surface 46.

The leaf spring 61 urges the wheel 17 into firm engagement with the coupler wheels 34, 36, 38 to insure maximization of the frictional forces produced in the transmission 31 and thus of the power transmissable by the transmission 31.

The mounting member 40 is preferably formed of sheet stock of such stiffness that the member 40 will flex somewhat when acted on by the spring 61 (through wheel 17). By this expedient, firm frictional engagement of the coupler wheels 34, 36, 38 with the track surface 46 on plate 33 is assured.

Due to the spring biasing together of the wheel 17, coupler wheels 34, 36 38, and plate 33, as described, and because of the slight natural wobble of the wheel 17 and plate 33, the transmission 31 is caused to be relatively immune to clogging by dirt and debris. If a foreign particle should be captured between one of the coupler wheels 34, 36, 38 and the wheel 17 (or plate 33), the wheel 17 (or plate) will yield and allow the coupler wheel or wheels to travel over the particle without causing a jamming of the transmission.

For some applications, it may be desirable to place a cover over the transmission 31, or, alternatively, the bracket 32 modified to substantially enclose the transmission so as to minimize the entry of dirt and debris into the transmission.

In operation, as the device 10 is moved over a surface being cleaned, frictional forces generated between the surface and wheel 17 and between track surface 46 on wheel 17 and the coupler wheels 34, 36, 38 cause the coupler wheels to rotate. Frictional forces produced between the coupler wheels 34, 36, 38 and track surface 46 on driven plate 33 cause the plate 33, and thus the brush 14, to rotate in a direction opposed to the direction of rotation of the wheels 16, 17.

The device 10 includes a left end bracket 70, here shown as having an apertured left arm (not shown) for supporting the left end of stub axle 18 and a right arm for supporting the left end of brush 15. The right arm has an in-turned end which forms an apertured central member for supporting the right end of stub axle 18.

Thus, by this invention there is provided lightweight, highly maneuverable and low cost friction-driven rotary cleaning apparatus having an improved coaxial transmission which is substantially immune from clogging and jamming, which is relatively inexpensive to manufacture, and which has a number of other improvements and features as described above.

The invention is not limited to the particular details of construction of the embodiments depicted, and it is contemplated that various and other modifications and applications will occur to those skilled in the art. For example, rather than being of stamped sheet metal construction, as shown, the housing and at least part of the support means for the transmission, brush and wheels may be injection molded as a unit from a suitable plastic material. Other transmission structures may be devised by those skilled in the art to implement the teachings of this invention; as a further example, a number of coupler wheels other than three, as illustrated, may be employed, although three is preferred for reasons of maximized stability at lowest cost. Other support and mounting structures for the transmission elements may be used. The leaf spring 61 representing an extension of the right (outer) arm 62 of the bracket 32 may be eliminated and the end wall 29 apertured to support the right end of stub shaft 19. The bracket in this embodiment would have but two arms corresponding to the left (inner) arm 44 and the mounting member 40. The wheel 17 would be supported by the outer one of these arms and the end wall 29. A spring performing the function of spring 61 would preferably be disposed between the wheel 17 and the end wall 29. A similar modification could be made in the left end support structure for the brush shaft 15 and left drive wheel 16.

As used herein, the term stub axle is intended to mean any means for supporting for rotation a single wheel or equivalent surface friction-driven member, as opposed, for example, to a transverse axle which might extend across a device for supporting a pair of wheels on opposite sides of the device. Thus,a shaft which is affixed to a frame or housing for a device and which receives a wheel for rotation thereon is intended to be considered a stub axle.

Whereas the above depiction stresses the use of a rotary cleaning tool in the form of a cylindrical brush having bristles extending from a central shaft, the use of other surface treating tools capable of rotary operation in lieu thereof is within the compass of this invention and such tools are intended to be considered as equivalents thereof.

Therefore, because certain changes may be made in the above-described apparatus without departing from the true spirit and scope of the invention herein involved, it is intended that the subject matter of the above depiction shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In friction-driven cleaning apparatus including:

a cleaning tool having a longitudinal axis;

friction-driven means engaging the surface to be cleaned and rotatable on axle means as said apparatus is moved over said surface;

coaxial transmission means disposed between said friction-driven means and said cleaning tool for coupling said friction-driven means and said tool such that rotation of said friction-driven means effects rotation of said tool; and

support means for supporting said axle means of said friction-driven means, said transmission means, and said tool for rotation on a common axis;

the improvement wherein said coaxial transmission means comprises:

first means rotatable with said friction-driven means and having thereon a first circular track surface concentric with said common axis;

second means fixedly connected to said tool for rotation therewith having thereon a second circular track surface concentric with said common axis and disposed in spaced visa-vis relationship to said first track surface and;

at least one friction coupler means supported between said first and second means in frictional engagement with corresponding points on said first and second track surfaces and mounted for rotation about a fixed axis such that rotation of said first means in one direction causes said tool to rotate in the opposite direction.

2. The apparatus defined by claim 1 wherein said friction coupler means comprises a wheel having a high friction peripheral surface and wherein said first and second track surfaces are high friction tracks for engaging said wheel.

3. The apparatus defined by claim 2 wherein said coupler means comprises three wheels spaced at substantially equal angular intervals around said common axis.

4. The apparatus defined by claim 1 wherein said second means constitutes a part of said friction-driven means and wherein said apparatus includes axial-acting spring means for effectively urging said first means and said coupler means toward each other to impose and maintain compressive forces on said coupler means.

5. Ground and floor cleaning apparatus for cleaning dirt and debris from patios, sidewalks, and the like, comprising:

a cylindrical brush having bristles extending from a central shaft;

a pair of drive wheels of smaller diameter than said brush, one wheel being disposed at each end of said brush, said wheels being mounted on stub axles;

support means for rotatably supporting both ends of said brush shaft and for supporting said stub axles such that said wheels turn on a common wheel axis coaxial with said brush shaft;

coaxial transmission means supported on said common axis by said support means between at least one of said drive wheels and said brush for coupling said one drive wheel and said brush shaft such that rotation of said one drive wheel effects opposite rotation of said brush, said transmission comprising: driven member fixedly connected to said brush shaft and having thereon a first circular high friction track surface concentric with said common axis,

a second circular high friction track surface on said one drive wheel concentric with said common axis and disposed in spaced vis-a-vis relationship to said first track surface,

a plurality of angularly spaced high friction coupler wheels supported on independent fixed axes between said one drive wheel and said driven member, each in frictional engagement with corresponding points on said first and second track surfaces, and

axial bias means for effectively biasing into mutual compressive engagement said one drive wheel, said coupler wheels, and said driven member, whereby rotation of said one drive wheel in one direction is transmitted by frictional forces through said coupler wheels to said driven member to cause rotation of said brush in the opposite direction; and a handle joined to said support means such that said handle and said support means pivot together about said common axis.

6. The apparatus defined by claim 5 wherein said first and second track surfaces comprise surface irregularities formed on said one drive wheel and said driven member.

7. The apparatus defined by claim 6 wherein said support means includes a stamped sheet metal housing and bracket means secured to said housing, said bracket means having three forwardly extending arm means, an outer arm means for supporting one end of said stub axle of said one drive wheel, an inner arm means for supporting for rotation said driven member and said brush shaft, and a central arm means for supporting for rotation said coupler wheels and the other end of said stub axle.

8. The apparatus defined by claim 7 wherein said coupler wheels comprise three wheels with high friction peripheral surfaces spaced at equal angular intervals around said common axis.

wheels.

10. The apparatus defined by claim 9 wherein said axial bias means includes a leaf spring for urging said one drive wheel toward said coupler wheels. 

1. In friction-driven cleaning apparatus including: a cleaning tool having a longitudinal axis; friction-driven means engaging the surface to be cleaned and rotatable on axle means as said apparatus is moved over said surface; coaxial transmission means disposed between said friction-driven means and said cleaning tool for coupling said friction-driven means and said tool such that rotation of said friction-driven means effects rotation of said tool; and support means for supporting said axle means of said frictiondriven means, said transmission means, and said tool for rotation on a common axis; the improvement wherein said coaxial transmission means comprises: first means rotatable with said friction-driven means and having thereon a first circular track surface concentric with said common axis; second means fixedly connected to said tool for rotation therewith having thereon a second circular track surface concentric with said common axis and disposed in spaced vis-avis relationship to said first track surface and; at least one friction coupler means supported between said first and second means in frictional engagement with corresponding points on said first and second track surfaces and mounted for rotation about a fixed axis such that rotation of said first means in one direction causes said tool to rotate in the opposite direction.
 2. The apparatus defined by claim 1 wherein said friction coupler means comprises a wheel having a high friction peripheral surface and wherein said first and second track surfaces are high friction tracks for engaging said wheel.
 3. The apparatus defined by claim 2 wherein said coupler means comprises three wheels spaced at substantially equal angular intervals around said common axis.
 4. The apparatus defined by claim 1 wherein said second means constitutes a part of said friction-driven means and wherein said apparatus includes axial-acting spring means for effectively urging said first means and said coupler means toward each other to impose and maintain compressive forces on said coupler means.
 5. Ground and floor cleaning apparatus for cleaning dirt and debris from patios, sidewalks, and the like, comprising: a cylindrical brush having bristles extending from a central shaft; a pair of drive wheels of smaller diameter than said brush, one wheel being disposed at each end of said brush, said wheels being mounted on stub axles; support means for rotatably supporting both ends of said brush shaft and for supporting said stub axles such that said wheels turn on a common wheel axis coaxial with said brush shaft; coaxial transmission means supported on said common axis by said support means between at least one of said drive wheels and said brush for coupling said one drive wheel and said brush shaft such that rotation of said one drive wheel effects opposite rotation of said brush, said transmission comprising: a driven member fixedly connected to said brush shaft and having thereon a first circular high friction track surface concentric with said common axis, a second circular high friction track surface on said one drive wheel concentric with said common axis and disposed in spaced vis-a-vis relationship to said first track surface, a plurality of angularly spaced high friction coupler wheels supported on independent fixed axes between said one drive wheel and said driven member, each in frictional engagement with corresponding points on said first and second track surfaces, and axial bias means for effectively biasing into mutual compressive engagement said one drive wheel, said coupler wheels, and said driven member, whereby rotation of said one drive wheel in one direction is transmitted by frictional forces through said coupler wheels to said driven member to cause rotation of said brush in the opposite direction; and a handle joined to said support means such that said handle and said support means pivot together about said common axis.
 6. The apparatus defined by claim 5 wherein said first and second track surfaces comprise surface irregularities formed on said one drive wheel and said driven member.
 7. The apparatus defined by claim 6 wherein said support means includes a stamped sheet metal housing and bracket means secured to said housing, said bracket means having three forwardly extending arm means, an outer arm means for supporting one end of said stub axle of said one drive wheel, an inner arm means for supporting for rotation said driven member and said brush shaft, and a central arm means for supporting for rotation said coupler wheels and the other end of said stub axle.
 8. The apparatus defined by claim 7 wherein said coupler wheels comprise three wheels with high friction peripheral surfaces spaced at equal angular intervals around said common axis.
 9. The apparatus defined by claim 8 wherein said central arm means has three apertures therein for receiving said coupler wheels, and wherein said central arm means supports three axles transversely of said apertures for mounting for rotation said coupler wheels.
 10. The apparatus defined by claim 9 wherein said axial bias means includes a leaf spring for urging said one drive wheel toward said coupler wheels. 